How to exclude certain columns by column names?

Try this:
  

x[, colnames(x) != 'a']
    

[1] 3 4

On Tue, Nov 3, 2009 at 9:31 AM, Peng Yu <pengyu.ut at gmail.com> wrote:
  

I can exclude columns by column number using '-'. But I wondering if
there is an easy way to exclude some columns by column names.

    

x=cbind(c(1,2),c(3,4))
x
      

    [,1] [,2]
[1,]    1    3
[2,]    2    4
    

colnames(x)=c('a','b')
x
      

    a b
[1,] 1 3
[2,] 2 4
    

x[,-'a']
      

Error in -"a" : invalid argument to unary operator
    

x[,-1]
      

[1] 3 4